Hongjun Song, Ph.D., of the Johns Hopkins School of Medicine, is intrigued about niches in a brain structure called the hippocampus where stem cells live and can give rise to new neurons, a process called neurogenesis. With the support of a 2008 NARSAD Independent Investigator Grant, Dr. Song and team developed a genetic strategy for tracing the life cycle of precursor cells in the brain. What they found was that any single stem cell is capable of both replacing itself and of giving rise to both neurons and glia.
They also discovered that a lone stem cell can generate two new stem cells; that is, stem cells don’t just maintain the numerical status quo, or deplete in number, they can amplify their number. In discussing this last, unexpected finding, Dr. Song observed: “If we can somehow cash in on this newly discovered property of stem cells in the brain, and find ways to intervene so they divide more, then we might actually increase their numbers instead of losing them over time, which is what normally happens, perhaps due to aging or diseases.”
“If we use stem cells to quickly find effective drugs that can become common treatments, there will be a greater impact and more widespread benefit than with transplants which, because of being case-by-case, will be expensive.”
Dr. Song and team’s findings have significance for understanding processes involved in depression and schizophrenia, among other illnesses. Stem cell technology enables researchers to not only recreate models of disease to study mechanisms underlying the illnesses, but it also offers promise as a screening tool for novel medications. This emerging technology and capacity may also lead to the development of regenerative medicine opportunities for patients with these illnesses.